The NHS Trust Stoke Mandeville Hospital, which is presently at the centre of a superbug scandal, was given the lowest infection-control rating in a recent set of NHS performance indicators.
The Healthcare Commission said in its report that the trust's record on preventing the spread of bugs such as Clostridium difficile was "poor" and significantly below what was expected.
The Buckingham-shire hospital, despite having a world-famous reputation for its spinal unit at Stoke Mandeville, was awarded just one star in last year's performance ratings by the Healthcare Commission.
The ratings give NHS trusts between zero and three stars, based on a series of indicators such as infection control, waiting times and death rates.
Infection control is assessed on compliance with national standards and levels of controlling bugs picked up while patients are in hospital.
The Buckinghamshire Hospitals Trust was only given a "one" rating for infection control, the lowest possible mark, and out of 177 other acute NHS trusts only 17 were given a similar score, with the majority being rated as acceptable or good.
The trust was also told it was "significantly underachieving" in terms of financial management, another reason for its one-star status.
The trust says that a key aim in its plan for 2005, is to achieve two stars in the performance ratings.
According to a spokesman the trust broke even last year and was addressing the issues raised in the performance indicators.
The rating reflects poorly on the world-famous hospital, whose incidents of C. difficile, which produces hardy spores that are resistant to some methods of cleaning, have raised fresh concerns about deteriorating cleanliness.
Those fears were fuelled when the public service union Unison warned that hospital cleaners were being told to clean as many as four wards in an hour by private companies eager to cut costs and raise profits.
A chronic shortage of cleaners and a high turnover of poorly paid staff was adding to the problem of hospital infections, says the union.
The union says the number of full-time cleaning staff has fallen by 45 per cent in the 20 years since services were "contracted out" of the NHS to private companies. In 1986, there were 67,000 full time cleaners in the health service - now there are just 36,000.
Dave Prentis, general secretary of Unison, says Government and hospital managers should listen to hospital cleaners when they say what is needed is more staff, better equipment, proper training, effective teamwork and greater involvement in decision-making.
Prentis says Unison would like to see hospital cleaning brought back in-house and under the direct control of staff on the wards.
The cleaning contract at Stoke Mandeville was held jointly by two private companies, but next year the hospital plans to second members of staff under a new type of contract to another company which would allow it to retain responsibility for the staff and for standards of hygiene.
The revelations about Stoke Mandeville has prompted some to come to its defence.
The former television presenter and radio DJ Sir Jimmy Savile who is a prominent fundraiser and patron of the hospital, says "the hospital has done everything it can to tackle this problem and people should feel safe about coming here".
Sue Wiseman, the infection control adviser to the Royal College of Nursing, says specialist units such Stoke Mandeville present a particular problem because they have patients being transferred from hospitals up and down the country, which adds to the spread of infection. It is also an old hospital, which means it has lots of nooks and crannies that can be hard to clean.